Fire suppression systems are common in many of today's structures and to some extent in many vehicles. The type of system used is often dependent on the application and/or the type of hazard that is to be addressed. Some fire suppression systems also incorporate redundancy to protect against system failure. However, redundant systems are often merely just an increase in one or more of the same components in a system. The reasoning for this is that the probability of both systems failing simultaneously is much less than the probability of failure for a single system. However, redundant systems comprising multiple system components can add cost and each system may be subject to the same type of failure mode.
Redundancy in fire suppression systems has also been accomplished by combining systems that operate independently of each other. For example, an electrically controlled system may be backed up by a pneumatic system that is not subject to electrical failure. Although potentially better in some applications, redundancy performed in this manner results in two different active systems which can also increase cost and complexity.